A tearful President Barack Obama said Tuesday that he was taking executive action, bypassing Congress, to implement new "common-sense" measures aimed at reducing gun violence in America.

“In Dr. [Martin Luther] King’s words, we need to feel the fierce urgency of now, because people are dying,” a visibly emotional Obama told an audience of mass shooting victims and relatives at the White House.

“Our inalienable right to life and liberty and the pursuit of happiness, those rights were stripped from college kids in Blacksburg and Santa Barbara and from high schoolers at Columbine, and from first-graders in Newtown,” he said, listing the various shooting sprees at schools across the United States.

This is a look at the unique relationship between Americans and their guns.

Second Amendment

Any law-abiding citizen in the United States is allowed to own or carry a gun.

That right comes from the Bill of Rights and the Second Amendment to the U.S. Constitution. It says: "A well-regulated militia, being necessary to the security of a free state, the right of the people to keep and bear arms, shall not be infringed."

The Second Amendment was based partly on English common law, which describes an auxiliary right, supporting the natural rights of self-defense, resistance to oppression and the civic duty to act in concert in defense of the state.

The ease of ownership

To purchase a gun in the majority of states, one needs only to be of legal age, pass the FBI’s National Instant Criminal Background Check and fill out a firearms transaction record.

However, background checks are not currently required for private sales, including those conducted at gun shows.

Certain people are banned from owning weapons, including convicted criminals, people with mental illnesses or non-U.S. citizens. But the system has major holes in it.

The debate

Pro-gun ownership: The wording of the Second Amendment is the primary defense cited by gun rights advocates. They say Americans have a constitutional right to arm themselves.

Many supporters are quick to point out that stricter gun laws have not ended gun violence in cities such as Chicago and Washington. Gun owners say guns give people the power of self-defense, dissuading criminals from victimizing people who might be armed. That argument appears to gather momentum with every report of a mass shooting.

Pro-gun control: Those advocating stricter laws cite statistics to bolster their case. The Centers for Disease Control and Prevention reports that in 2013, there were more than 33,000 firearms deaths in the U.S.

They point to countries like Japan where gun control laws are strict and shooting deaths are almost nonexistent. They argue that better records on gun ownership and more stringent laws regarding the sale, possession and storage of guns would allow law-abiding people to have firearms, while resulting in far fewer accidental deaths, suicides and homicides.

The reality

The debate on guns has played out many times in American history. But regardless of where one falls, the fact remains that U.S. gun ownership is exceptionally high and growing. According to the Small Arms Survey, the United States has an average of 116 guns per 100 people, although most of those weapons are owned by a minority of citizens.

The United States is home to roughly 35 to 50 percent of the world’s civilian-owned guns, even though it holds less than 5 percent of the world’s population.